Adjustable propeller device



-W. U- HUSStLL.

ADJUSTABLE PROPELLER DEVICE.

APPLI CATI'ON FILED DEC. 16- I919.

Patented June 6, 1922.

3 SHEETSSHEET I.

W. C. RUSSELL.

ADJUSTABLE PROPELLER DEVICE.

APPLICATION FILED 05c. I6. 1919.

1,41.8,38. P tente June 6, 1922.

3 SHEETS-SHEET -2.

W. C. RUSSELL.

ADJUSTABLE PROPELLER DEVICE.

APPLICATION FILED DEC.I6. 1919.

1,418,399. PatentedJune 6, 1922. V LU 3 SHEET$$HEET 3- umreo 115s;PA'rEN rice.

WILLIAIE COLIN RUSSELL, OF EAST SHEEN, ENGLAND.

ADJUSTABLE PROPELLER DEVICE.

Application filed December 16, 1919. Serial No. 345,300.

To all whom it may concern:

Be it known that I, \VILLIAM SELL, a subject of the King'of GreatBritain, residing at East Sheen, in the county of Surrey, England, haveinvented certain new and useful Improvements in Adjustable PropellerDevices, of which the following is a specification, reference being hadtherein to the accompanying drawings.

It is known that the general eflicieucy and utility of airscrews' usedfor the propulsion of aircraft can be increased byproviding means ofadjusting the angles of the airscrew blades to various angles abouttheir longitudinal axis during flight, to agree with changes in thespeed of the aircraft or fluctuation of engine power output, and anumber of constructions to this end have already been proposed. a

My invention has for its object to'providc improved means of pivoting,mounting and controlling the blades of an adjustable airscrew of thetype having the pivots of diametrically 'opposite blades telescoped oneCoLiN Ros within the other for the purpose of reducing structionalfeatures. a

to project beyondi-the farther end or nor-1 ima'l diameter) of. outer.pivot stem or the upon or attaching v-to; "mthewportion so pro ecting a.headcipiece :a'r-i ranged 'zso ,athata between the: said; headpiece. andrthe: adj acerit. end? of r fouter..p1votg stem can be. provided-s athrust.{bearing (p'referr;

purpose of formin 'while leaving. each pivot freedom to .-rota.t

Journal bearings are ,provided between the innerland outer pivots tosupport them later-j allybut with, freedom to; rotate about their 1longitudinal axis: Either got; or both the "pivots or interlockingheadpiece may be cong structed of two-or more partsfor the purbulk, andembodies the following con- .2 Diametrically opposite blades.constitutinga balancedwvorkingrpair; are eachmounted uponor formed inone .witlr apivot, their. YpiVOtvOf the one "being telescoped within the7 pivot 'of'the othenand the pair supported; "i in position in thefollowing, manner; I An. innertubiflarkor solidjpivotis' passed throughan- .outer tubular pivotgaiid arranged plate to which a detachable bladecan be i porting frame or T head so that the inner pivot is whollysupported Within the outer pivot, the latter being wholly supportedwithin the frame or alternatively, so that eachpivot of the pair issupported partially within or upon its fellow pivot and partiallydirectly within the said supporting frameor T head upon airscrew'shaft.

The two blades and pivots are arranged to be balanced inweight, and theradial pull on each blade, and pivot due to centrifugal force duringrotation of the airscrew is thus wholly taken up bv the. interlockingthrust bearing between the pivots;

-Leversmay beatt'achedto or formed upon the pivots for the purpose ofrevolving them to effect blade adjustment; herev use ,is made ofdetachable blades constructed :of. .Wood or .otherfi frailmaterial,arranged with conical ;o r,- tapered "butt ends (having; L their,largendiameter inmost) encasedin similarly conical or; tapered splitrmetal sockets as vaneans of .attaoh-ingthe blades to their; pivots Imay, {provide the ef l cwing: pe m an i fisec11r r g the split i"-"ably.arball bearing)fortheepurpose of fl) 1 .wterlocking the; pair of pivotslongitud nally 21:45,

- 'independently about its long ud al poseof assembling theminworkingposi-; tion. Each pivot may. be formed in onewith its blade,'0r maybeconstructed with an end meal: Timon tanei f high-te et. said: wire .ortapewn d ngs. serving the pursocke o t blade u t In ieu io fa m-.1lnagthea t spec ive,= sp i pa t f-1h aso ts with, flanges by which;they ,may be secured i ogeth nby o sanet..-. uzts a hither- 0 PTO- -pQdL,--.,the1. conic laor L- tapered. po o of gsplit; sockets--,.aregattached tg the; lane. butts ame ns P Qfa Mi ding e emi zpose ofmeetingrthe l ealvy r stress in .(1 ng, ,action the socket arising fromthe tot-the tapered blade Tbutt; ,ivhe i aided uponby,centrifugal;,force ili rmg rc drop The split socket's: may be led h"rcumferential flanges ;'or groo a tsuitable. intervals prevent the,wirewindings from slip- 1 )lng.- j1 h & use of inetal :wire ortapelsocket binding as proposed has a, speciahvalue under the conditionsof working of revolving airscrew blades in securing maximum strengthwith minimum weight, and it is obvious that this construction is notdependent upon any particular form of pivot mounting.

In order that the arrangement of blade mounting and pivoting embodied inmy invention may be the better understood the construction is furtherexplained by reference to the drawings appended hereto in which Figures1 and 2 are respectively a transverse section and an elevation of a pairof detachable blades and pivots the blades being fixed by wire boundsockets bolted to the pivot plates, the inner pivot having a detachableend by means of which the thrust bearing is secured in position and theblade adjustment being effected by means of a pair of annular gearwheels operated by band brakes.

Figure 3 is a corresponding horizontal cross section thereof.

Figure 4 is a transverse section of an engine shaft of current typeillustrating a modified arrangement of helically grooved wheel and innerpivot in conjunction with roller journal bearings.

In Figs. 1, 2 and 3 the airscrew shaft A is in this illustration of myinvention formed in one with a tubular T headpiece A in which issupported in ournal bearings, with freedom to rotate about itslongitudinal axis, the outer tubular pivot B t minating in the end plateB to which on of the airscrew blades may be bolted. Through the saidhollow pivot B is passed. the inner pivot C similarly supported thereinin journal bearings with freedom to rotate about its longitudinal axis,and upon the end of it opposite to B is formed a similar end plate C towhich the other airscrew blade of the pair may be bolted. The projectingend of the inner pivot C adjacent to the end plate B is formed as ascrew upon which is screwed f the nut head C arranged so that between itand the top of the stem of pivot B (or end plate B may be located thethrust bearing C illustrated in this drawing as a ball bearing. The nuthead C and thrust bearing C thus com lete the interlocking of'the pivotsB and I and each pivot is independently revoluble about its longitudinalaxis by means of the levers B? and G I do not limit myself to anyparticular means of operating these levers to effect blade adjustment.

To the end plates B and C are bolted the conical metal sockets P split(in halves in this illustration) so that they may be placed around thesimilarly conical butt ends R formed upon the wooden blades. The socketsP are secured to the butt ends R by being bound around with wire or tapeof high tensile strength, the windings P ings. The inner pivot C is hereillustrated as a bar with a tapering and screwed end,

and the end plate C (formed with asleeve.

to fit over the inner bar C) is secured to it by a nut C The head Cbearing upon the; thrust ball bearing C is formed in one with the bar G,the illustration emphasizing that the arrangement of the pivots toembody the interlocking thrust bearing may be varied whilst retainingthe general feature of interlocking telescoped pivots by a thrustbearing irrespective of how the latter is arranged. In the mounting ofthe pivots in the supporting frame, the neck of outer pivot B issupported in the roller bearing ring A and its body is further sup ortedon bearings upon the inner pivot The neck of inner pivot C is supportedin the roller bearing ring A and its body on bearings within the outerpivot. B, thus illustrating that the pivots may be mounted partiallydirectly with the supporting frame and partially within or upon eachother.

For the purpose of operatin the pivot adjusting levers of airscrewsaving the pivots of diametrically opposite blades telescoped one withinthe other, I provide the following device as an alternative to otherknown arrangements, the object of my improvement being to obtainsynchronized movement of the blade levers 'in opposite directions, withmeans for rapidly synchro-' nizing the setting, and an irreversible operating mechanism whereby it is not necessary to maintain revolving partsunder continuous pressure or tension for the purpose of holding theblade levers in any desired position.

To. this end I attach levers to each pivot of a working pair of bladesarranged so that pins or the like located at the extremities ofthelevers-may engage substantially at diametrically opposite sides in oragainst a groove or cam face cut in a drum or wheel revolubly mountedbetween the levers, the said grooved or cam faced drum or wheel being soarranged that its rotation causes equal and opposite movement of thepivot levers. I Preferably I may employ a grooved drum having a grooveof uniform Pitch cut 125 Y in its periphery giving left hand movementfor one half the circumference and right hand movement for the remaininghalf i. e. the groove is endless traversing from one side ofthe drum tothe other and back 13a may be provided whereby the said groovedwheel ordrum can be adjusted longitudinally in relation to its axis.

Motive power for rotating the said grooved wheel or drum in eitherdirection may be provided by any convenient form of gearing, butarranged preferably with the final drive to the drum conveyed through aworm and worm wheel in order that the drum may be completelyirreversible by any pressure from the pivot levers.

The construction is more fully explained by reference to drawings Figs.1, 2, 3 and 4 ended hereto.

n Figs. 1, 2 and 3, the blade pivots have attached to them levers B andC terminating respectively in the pins B and C whicheng'age in a helicalgroove D cut'in the drumD which is mounted between the said pins upon anaxle D so that the pins engage at diametrically opposite points in itsperiphery. Figs. 2 and 8 show the groove cut uniformly with right handmovement for half the circumference of drum D and left hand or reversemovement for the remainder, thus when the drum D is rotated upon itsaxle D the pin and lever B is moved in one direction and the pin andlever C in the opposite direction an approx1- mately equal distance.Adjusting screws D permit of' adjustment of the drum setting axially.

The drum D is here illustrated as having attached to it a worm wheel Ddriven by the worm E mounted upon the driving shaft E located at theside of airscrew hub and driven either, forward or backward by lmechanism of any convenient type arovided for this purpose and notillustratec herein.

The drum D is .illustrated as mounted across the axis of rotation of theairscrew for ,convenience of rotational balance. In Fig. 4 the drum D ismounted in an alternative position, illustrating that the drum may bemounted in any convenient position.

I claim 1, The combination with a propeller shaft and a propeller havingblades pivotally I mounted in the propeller hub, of .a tubular pivotformed with an end plate, a conical split metal socket secured to saidplate in which socket the butt end of one-of the blades is secured, awinding of high tensile strength about said socket, an inner pivotpassing through'and supported in the tubular pivot and formed withan endplate, a conical split metal socket secured'to said end plate =nerpivot, a thrust in which socket the l 'tt end of the other of the bladesis secured, a winding of high tensile strength about said socket, alaterally extending lever on each of said pivots, a nut .head on theprojecting end of the inbea'ring between the said head and the end ofthe tubular pivot, and

means actuated by the propeller shaft for" operating the said laterallyextending levers so as to turn the said pivots in opposite directions inthe propeller hub.

v 2. The combination with a propeller shaft and a propeller havingblades pivotally mounted in the propeller hub, of a tubular pivot;formed with an end plate, a conical split metal socket secured to saidplate in which socket the butt end of one of the blades is,

secured said socket having grooves on the exterior thereof, windings ofhigh tensile strength in said grooves about said socket, an inner pivotpassing through and supported in the tubular pivot and formed withan'end plate, a conical split metal socket secured to said end plate inwhich socket the butt end of the other of the blades is secured, saidlast named socket having grooves on the exterior thereof, windings ofhigh tensile strength in said grooves about said socket, a laterallyextending lever on each of said pivots, a nut head on the projecting endof the inner pivot, a thrust bearing between the said head and the endof the tubular pivot, and means actuated by the propeller shaft foroperating the said laterally extending levers so as to turn the saidpivot in opposite directions in the propeller hub.

'3. The combination with a propeller shaft and a propeller having bladespivotally mounted in the propeller hub, of a tubular pivot supported injournal bearings in the propeller hub and formed with an end plate towhich one of the blades is attached, an

inner pivot passing through and supported in journal bearings in thesaid tubular )ivot and formed with an end plate to whlch the other ofthe blades is attached, a nut head on the projecting end of the innerpivot, a thrust ball bearing between the said head and the end of thetubular pivot, a laterally extending lever on each of said pivots, aterminal pin on each of said levers, a helically grooved drumforengagement by said pins, means for adjusting said drum longitudinallyin relation to its axis, and means actuated by the propeller shaft foroperating the said drum so as to deflect said levers and turn the saidpivots in opposite directions in the propeller hub.

4:. The combination with a propeller shaft and a propeller having bladespivotally mounted in the propeller hub, of an outer tubular pivotsupported partly in a hubroller bearing ring, an inner tubular pivotalso supported partly in ahub roller hearing ring said pivots being alsopartly supported in journal bearings the one Within the other, an endplate on each of said pivots to which the propeller blades arerespectively attached, a nut head, a thrust ball bearing between saidhead and the end of the outer tubular pivot, a laterally extending leveron each of said pivots, a terminal pin on each of said levers, ahelically grooved drum for engagement by said pins, means for adjustingsaid drum longitudinally in relation to its axis, and means actuated bythe propeller shaft for operating said drum so as to deflect said leversand turn the said pivots in opposite directions-in the, pro-- pellerhub.

5. In a revoluble variable pitch propeller for aircraft, the combinationWith the propeller shaft having telescopic blade pivots, of a mountingfor said pivots consisting of a frame mounted on the propeller shaft andantifriction rings on said mounting, each of which embraces the neckportion of one of the pivots, the shaft portions of said pivots beingborne by journal bearings respectively within and=upon each other.

In testimony whereof I aflix my signature in presence of tWo witnesses.

W. COLIN RUSSELL.

Vitnesses:

J. B. RIOHMAN, A. E. BRoUNeER.

